> Tapping a PCIe signal should be doable, but it would take some > serious engineering at the electrical level. What I'd try is to tap the > transmission line with a 3-arm T attenuator, with most of the power passing > straight through, and a greatly attenuated signal coming out the side arm. > Then terminate the side arm, and amplify back to standard logic levels for > compatibility with a logic analyzer. The tap adapter would have to be > implemented as a microwave PC board, with connectors to plug between the > device and the cable.
Let's call yours as an analog tap. I think you can make a digital one too - place an LVDS receiver, then divide the signal to 2 directions, one for LVDS transmiter (pass-thru path) and the other one to the data recorder device. This setup goes num_lanes x 2 times (for each direction) and +1 for the reference clock. It should require only a standard PCB (with differential lines). The thing I would be most worried about here is the delay introduced by the tapping component (e.g. a small FPGA sitting between the mobo and the card). D. _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
